Unlike most top-level domains (TLDs), .AT domains can only be registered for one year at a time. As a result, you can't renew a .AT domain more than one year in advance, and it must be renewed at least 5 days before its expiration date.

If not renewed by the 5th day before the expiry date, the domain will be removed from your Dynadot account. At that point, you may lose ownership or need to pay a restore fee to recover it (if available).